Triple-Chocolate Skillet Brownie with Molten Hazelnut Core Step-by-step instructions

Before you start

Before starting, measure all ingredients and chop the chocolate. Freeze the hazelnut praline paste in a disc shape—spoon it onto a parchment-lined plate and freeze for at least 2 hours, or overnight.

Heat the oven to 350°F (175°C) and butter the skillet. Set up a double boiler or have a microwave ready for melting the chocolate and butter. Have all bowls and utensils at hand, as the batter comes together quickly.

Instructions

Melt and Whip

1. 1Melt Chocolate and Prep Pan
   Heat the oven to 350°F (175°C). Butter a 10-inch cast-iron skillet. In a heatproof bowl set over a pan of barely simmering water, melt the chopped semi-sweet chocolate and butter together, stirring occasionally until smooth. Remove from heat and let cool slightly while preparing the eggs.
   Look for The chocolate and butter mixture should be glossy and fully melted, with no lumps.
   Tip If using a microwave, heat in 30-second bursts, stirring between each, to avoid scorching.
2. 2Whip Eggs and Sugars
   In a large bowl, combine the eggs, dark brown sugar, and granulated sugar. Beat with an electric mixer on medium-high speed for 5 minutes, until the mixture is pale, thick, and frothy. This step builds the shiny, crackly crust on top of the brownie.
   Look for The egg mixture should fall from the whisk in a thick ribbon that slowly dissolves.
   Tip Beating the full 5 minutes is essential for the classic crinkly top.
3. 3Add Chocolate and Dry Ingredients
   Pour the melted chocolate-butter mixture into the egg mixture and whisk gently until glossy and fully combined. In a separate bowl, whisk together the flour, cocoa powder, and sea salt. Fold the dry ingredients into the wet mixture with a rubber spatula until just combined, with no streaks of flour.
   Look for The batter should be thick, glossy, and uniform in color.
   Tip Do not overmix once the flour is added; overmixing can make the brownie tough.

The chocolate-butter mixture is smooth and glossy. The egg-sugar mixture is pale, thick, and has tripled in volume after beating. When you lift the whisk, the batter falls in a thick ribbon that slowly dissolves on the surface. The dry ingredients are whisked together, ready to fold in.

Assemble and Bake

4. 4Assemble the Skillet Brownie
   Pour half of the brownie batter into the prepared skillet and spread it evenly. Arrange the frozen discs of hazelnut praline paste in a single layer in the center, leaving a 1-inch border. Pour the remaining batter over the discs, covering them completely and smoothing the top.
   Look for The hazelnut discs should be fully hidden under the batter, but not touching the edges.
   Tip Keep the discs frozen until the last moment so they don't melt into the batter.
5. 5Bake the Brownie
   Bake the brownie at 350°F (175°C) for 22 minutes, until the edges are set and the top forms a shiny, crackly paper-like crust. The center should still look slightly moist and soft. A toothpick inserted 2 inches from the edge should come out with a few moist crumbs, but the center will remain gooey.
   Look for The top will puff slightly, then crack as it cools; the edges will be firm and the center will jiggle just a little.
   Safe temperature 160°F (71°C) internal temperature (egg dishes)
   Tip Start checking at 20 minutes—ovens vary, and the brownie is best when the center is still molten.

The batter is evenly spread in the skillet, with the frozen hazelnut discs hidden in the center.

As the brownie bakes, the top turns shiny and crackly, the edges set, and the kitchen fills with the smell of chocolate and toasted hazelnuts. The center should still have a slight wobble when you gently shake the skillet.

Top and Serve

6. 6Top and Serve
   Remove the skillet from the oven and let it cool on a wire rack for 5 minutes. Sprinkle the dark chocolate chunks over the hot brownie so they soften and begin to melt. Scoop vanilla bean ice cream on top, then drizzle with extra chocolate fudge if desired. Serve warm, scooping from the skillet.
   Look for The chocolate chunks should be glossy and slightly melted, and the ice cream should start to melt against the warm brownie.
   Tip For the best texture contrast, serve immediately while the brownie is still warm.

The brownie has cooled for a few minutes, the chocolate chunks have softened and melted slightly, and the vanilla ice cream is melting into the warm brownie. The first scoop reveals the molten hazelnut lava flowing out. Serve immediately for the best texture contrast.

Common mistakes

One common mistake is overbaking the brownie, which dries out the center and ruins the molten core. Start checking at 20 minutes and trust the visual cues: the edges set while the center remains soft.

Another mistake is not beating the eggs and sugar long enough—skipping the 5-minute whip results in a denser, less crackly top. Also, make sure the hazelnut discs are fully frozen; if they thaw, they'll melt into the batter and you'll lose the lava effect.

How to tell it’s done

The brownie is done when the edges are set and pull away slightly from the skillet, and the top has formed a shiny, crackly crust. The center will still look moist and soft—this is what you want.

To check, insert a toothpick about 2 inches from the edge; it should come out with a few moist crumbs, not wet batter. The internal temperature of the egg mixture should reach at least 160°F (71°C) to ensure the eggs are fully cooked.

• Egg dishes: 160°F (71°C) in the thickest part